alpha and beta blockers Flashcards
Phenoxybenzamine MoA and use
nonselective, irreversible alpha blocker
Pheochromocytoma (used preoperatively) to prevent catecholamine (hypertensive) crisis
Phentolamine MoA and use
nonselective, reversible alpha blocker
Give to patients on MAO inhibitors who eat tyramine-containing foods
nonselective alpha blocker side effects
Orthostatic hypotension, reflex tachycardia
Prazosin, terazosin, doxazosin, tamsulosin MoA and use
α1 selective (-osin ending)
Urinary symptoms of BPH; PTSD (prazosin); hypertension (except tamsulosin)
α1 selective (-osin ending) blocker side effects
1st-dose orthostatic hypotension, dizziness, headache
Mirtazapine MoA and use
α2 selective blocker
depression
Mirtazapine side effects
Sedation, serum cholesterol, increased appetite
Acebutolol, atenolol, betaxolol, carvedilol, esmolol, labetalol, metoprolol, nadolol, nebivolol, pindolol, propranolol, timolol
(-olols)
MoA
β-blockers
β-blockers (-olols) clinical use (6)
Angina pectoris MI SVT (metoprolol, esmolol) Hypertension HF Glaucoma (Timolol)
Effects of β-blockers on Angina pectoris
decrease heart rate and contractility, resulting in decreased O2 consumption
Effects of β-blockers on MI
β-blockers (metoprolol, carvedilol, and bisoprolol)
decrease mortality
Effects of Metoprolol, Esmolol on SVT
decrease AV conduction velocity (class II antiarrhythmic)
Effects of β-blockers on Hypertension
decrease cardiac output, decrease renin secretion (due to β1-receptor blockade on JGA cells)
Effects of β-blockers on HF
decrease mortality in chronic HF
Effects of Timolol on Glaucoma
decrease secretion of aqueous humor
β-blockers toxicity
Impotence, cardiovascular adverse effects (bradycardia, AV block, HF), CNS adverse effects (seizures, sedation, sleep alterations), and asthma/COPD exacerbations
which β-blocker has the side effect of dyslipidemia?
Metoprolol
β-blocker should be avoided in which patients due to risk of unopposed α-adrenergic receptor agonist activity?
cocaine users
Despite theoretical concern, what condition are β-blockers not contraindicated
Despite theoretical concern of masking hypoglycemia in diabetics, benefits likely outweigh risks
acebutolol (partial agonist), atenolol, betaxolol, esmolol, metoprolol have what selectivity?
β1-selective antagonists (β1 > β2)
nadolol, pindolol (partial agonist), propranolol, timolol have what selectivity?
Nonselective antagonists (β1 = β2)
carvedilol, labetalol have what selectivity?
Nonselective α- and β-antagonists
Which β-blocker activates NOS in vasculature and how?
Nebivolol combines cardiac-selective β1-adrenergic blockade with stimulation of β3-receptors, which activate nitric oxide synthase in the vasculature
